TYPE-SPECIFIC ANTIGENS, M AND T, OF MATT AND GLOSSY VARIANTS OF GROUP A HEMOLYTIC STREPTOCOCCI.

1. Two qualitatively different type-specific antigens, designated M and T, have been found present in matt variants of group A hemolytic streptococci, but only one of these, the T antigen, occurs in the degraded glossy variant. 2.

CANCERS DERIVING FROM THE VIRUS PAPILLOMAS OF WILD RABBITS UNDER NATURAL CONDITIONS.

The naturally occurring virus papillomas of western cottontail rabbits become malignant occasionally. The cancers derive from the papilloma cells, that is to say from elements already rendered neoplastic by the virus and still infected therewith. Papillomas produced with the virus in jack rabbits and snowshoe rabbits become cancerous in the same way but much more frequently, as is the case in domestic rabbits also.

ON CROSS REACTIONS OF EGG ALBUMIN SERA.

Experiments are presented on the cross reactions of hen egg albumin immune sera with egg albumins of other species by means of exhaustion with heterologous proteins and by inhibition tests. From the results it can be concluded that the sera contain multiple, qualitatively distinct antibodies. For this, two not mutually exclusive explanations come into consideration: the presence in proteins of a number of different, perhaps similar, complex determinants, and the fact, established by previous results, that one antigenic grouping can call forth the formation of diverse antibodies.

ELECTROPHORESIS OF PEPSIN.

1. A number of pepsin solutions containing several protein components have been studied by the electrophoresis method. All samples show a homogeneous boundary moving to the anode at pH 4.

SOME CHEMICAL ASPECTS OF THE POTASSIUM EFFECT.

The ability of Nitella to distinguish electrically between Na(+) and K(+) (potassium effect) appears to depend on several organic substances (or groups of substances). Of these R(MK) and R(SK) determine the mobility and partition coefficient (S) respectively of K(+) while R(MNa) and R(SNa) do the same for Na(+). These substances can vary independently and this variation is susceptible to experimental control.

SOME CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA.

Treatment of elementary bodies of vaccinia with dilute solutions of sodium hydroxide resulted in the extraction of certain soluble materials accounting for half of the dry weight of the virus. Elementary bodies contained about 0.4 per cent inorganic phosphorus, practically all of which occurred in the form of a nucleoprotein containing thymus nucleic acid.

A DISTINCTIVE SUBSTANCE ASSOCIATED WITH THE BROWN-PEARCE RABBIT CARCINOMA : II. PROPERTIES OF THE SUBSTANCE: DISCUSSION.

The serologically active substance of the Brown-Pearce tumor, a complement-fixing antigen, differs notably from certain other tissue antigens (the Wassermann, Forssman, and organ- and species-specific tissue haptens, for example) in the fact that it is not effective after alcoholic extraction of the tissue containing it. Like many of the proteins and viruses it is in-activated upon heating to 65 degrees C. for 30 minutes; and, like them as well, its activity is lost upon treatment with acid (to pH 4.

A DISTINCTIVE SUBSTANCE ASSOCIATED WITH THE BROWN-PEARCE RABBIT CARCINOMA : I. PRESENCE AND SPECIFICITY OF THE SUBSTANCE AS DETERMINED BY SERUM REACTIONS.

A substance is regularly present in saline extracts of the Brown-Pearce rabbit carcinoma growth which is capable of fixing complement specifically in mixture with the sera of certain rabbits bearing the tumor or in which this has recently retrogressed, as the foregoing experiments have shown. The substance was not demonstrable in extracts of the normal tissues, virus papillomas, or uterine cancers of rabbits, nor in extracts of rabbit tissues infected with certain viruses (vaccine virus, Virus III, fibroma virus). The sera of normal rabbits, of those immune to a variety of infectious diseases, including syphilis, vaccinia, fibromatosis, and Virus III, and of others with uterine cancers or virus-induced papillomas, failed to fix complement specifically in mixture with extracts containing the antigen of the Brown-Pearce tumor.

THE RESTORATION OF LOST ORGAN TISSUE : THE RATE AND DEGREE OF RESTORATION.

1. When half of the total kidney, suprarenal, ovarian, or testicular mass is removed the rate of growth of the remaining half is independent of the rate of growth of the organ at the time of removal. 2.

FAMILIAL MAMMARY TUMORS IN THE RABBIT : IV. THE EVOLUTION OF AUTONOMY IN THE COURSE OF TUMOR DEVELOPMENT AS INDICATED BY TRANSPLANTATION EXPERIMENTS.

A series of experiments is described in which fragments derived from two mammary tumors of distinct types were transferred at different developmental stages to the anterior chamber of the eye of normal rabbits. It was found that the ability to survive and to grow progressively after transplantation was not immediately related to anaplastic cellular changes. On the other hand, there existed a definite correlation between the success of transplantation and the morphological relationship of tumor cells and the normal cells of the host.

STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS : VII. SKIN SENSITIZATION BY INTRAPERITONEAL INJECTIONS.

A method has been described by which sensitization to a simple chemical, picryl chloride (2:4:6 trinitrochlorobenzene), can be satisfactorily attained by means of intraperitoneal injection of the compound when killed tubercle bacilli suspended in paraffin oil were used as adjuvant. Sensitivity of the contact dermatitis type results therefrom. It follows that although skin sensitization of this type is most easily obtained by dermal application this route of administration is no necessary condition for such sensitivity.

SEROLOGICAL TESTS FOR HOMOLOGOUS SERUM PROTEINS IN TISSUE CULTURES MAINTAINED ON A FOREIGN MEDIUM.

Connective tissue cells (fibroblasts) derived from skeletal muscle of 12 day old chick embryos were cultivated for almost 8 months (35 weekly passages) in rabbit plasma and rabbit embryo tissue juice diluted with Tyrode's solution. When fluids separated from these cultures were tested with immune precipitins developed against chicken serum, they gave positive reactions which showed no tendency to diminish with an increasing number of culture generations. Barring the intervention of unknown precipitable substances, these results indicate that connective tissue can produce proteins which are identical with, or closely related to, serum proteins.

CHARACTERISTICS OF A STRAIN OF LYMPHOCYTIC CHORIOMENINGITIS VIRUS ENCOUNTERED AS A CONTAMINANT IN TISSUE CULTURES OF RABIES VIRUS.

A strain of lymphocytic choriomeningitis virus has been encountered, which grows readily in mouse embryo, serum, Tyrode culture media. Its origin is not definitely known but appears to be either the mouse brain tissue or, more probably, the monkey serum. This strain gives clear cut results on filtration tests through Elford membranes, establishing the size of the virus, according to formula, as 33 to 50 mmicro.

BEHAVIOR OF WATER IN CERTAIN HETEROGENEOUS SYSTEMS.

In various models designed to imitate living cells the surface of the protoplasm is represented by guaiacol which acts in some respects like certain protoplasmic surfaces. The behavior of water in these models presents interesting features and if these occur in vivo, as appears possible, they may help to explain some of the puzzling aspects of water relations in the living organism. When sufficient trichloroacetic acid is added to a two-phase system of water and guaiacol the two phases fuse into one.

THE REACTIONS OF IODINE AND IODOACETAMIDE WITH NATIVE EGG ALBUMIN.

The following experimental results have been obtained. 1. Native egg albumin treated with iodine and then denatured no longer gives a nitroprusside test or reduces dilute ferricyanide in neutral Duponol PC solution.

STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : IV. INFECTION IN THE MOUSE WITH FRESH AND FIXED VIRUS.

A fresh strain of equine encephalomyelitis virus is infectious for adult mice in high dilutions by all modes of peripheral inoculation. A fixed strain has very limited invasive power when injected peripherally unless virus is placed in fairly close contact with nerve cell bodies, as in the intranasal or intraocular routes. For fixed virus the effectiveness of the mode of inoculation may be graded in the following descending order: intracerebral, intraocular and intranasal, intravenous, intraperitoneal, intramuscular, subcutaneous.

AN ELECTROPHORETIC STUDY OF NEPHROTIC SERA AND URINE.

The electrophoretic patterns of the sera and urine of two cases of lipoid nephrosis have been obtained and have been compared with a typical pattern of normal serum. The patterns of the pathological sera deviated widely from the normal, indicating relatively low albumin and high globulin content. The comparison of the patterns of nephrotic sera cleared by centrifugation and by ether extraction shows that a large portion of the beta globulin consisted of a labile lipo-protein.

A SOLUBLE ANTIGEN OF LYMPHOCYTIC CHORIOMENINGITIS : II. CHARACTERISTICS OF THE ANTIGEN AND ITS USE IN PRECIPITIN REACTIONS.

The soluble antigen of lymphocytic choriomeningitis which is readily separable from the virus is a relatively stable substance and appears to be of a protein nature. A specific precipitin reaction can be demonstrated when immune serum is added to solutions of antigen which have been freed of certain serologically inactive substances. The complement-fixation and precipitation reactions which occur in the presence of immune serum and non-infectious extracts of splenic tissue obtained from guinea pigs moribund with lymphocytic choriomeningitis seem to be manifestations of union of the same soluble antigen and its antibody.

STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : V. HISTOPATHOLOGY IN THE MOUSE.

In mice affected with equine encephalomyelitis, the first pathological disturbance in infant animals is an inflammatory reaction, which is usually less pronounced in adult animals. A characteristic type of parenchymal damage appears to be independent of the inflammation. In such foci of injury there is initially a vacuolation of intercellular tissue.

THE EFFECT OF DIETARY PROTEIN ON THE COURSE OF NEPHROTOXIC NEPHRITIS IN RATS.

Acute nephritis of medium severity, affecting both glomeruli and tubules, was produced in rats by injections of anti-rat-kidney serum, given on 3 consecutive days. The course of the nephritis was markedly influenced by the type of diet which was fed. Rats tended to recover promptly from the induced nephritis when a low protein-high carbohydrate diet was given.

THE MASKING EFFECT OF EXTRAVASATED ANTIBODY ON THE RABBIT PAPILLOMA VIRUS (SHOPE).

The foregoing experiments have shown that the causative virus is usually "masked" in the large, disorderly, fissured and inflamed papillomas of cottontails when antiviral antibody is present in quantity in their blood, though virus can be recovered as a rule from the smaller, discrete, well ordered papillomas of these rabbits, almost irrespective of the amount of antibody in the blood of the individuals bearing them. Other findings are described which indicate that the masking of the virus in the large fissured growths is due to serum antibody present in them as result of exudation or hemorrhage, which neutralizes the virus when the growths are extracted or preserved in vitro. The local conditions that favor extravasation of serum (and the accumulation of antibody) prevail as a rule in the large, confluent growths arising after virus has been sown broadcast on scarified skin, but to lesser extent or not at all in the discrete papillomas that occur naturally or as result of tattoo inoculation.

EXPERIMENTAL STUDIES OF THE VIRUS OF INFECTIOUS AVIAN ENCEPHALOMYELITIS.

The results of investigations thus far carried out on experimental avian encephalomyelitis indicate that the virus of this newly described disease conforms to the group of definitely established viruses. It was essential to determine its taxonomy since the only prior record of its study (1) defines the infective agent as a virus because the usual cultural attempts failed to reveal a visible microorganism to be identified with it, and because the transmissible agent passed through Seitz and Berkefeld N filters. At the present time such determinants fail completely to satisfy the criteria for defining a virus and their acceptance would lead to the inclusion of certain filtrable microbic agents, difficult to reveal except by special cultural procedures, as viruses (10).

ON THE PERMEABILITY OF THE STOMACH MUCOSA FOR ACIDS AND SOME OTHER SUBSTANCES.

1. Solutions approximately isotonic with blood of strong and weak acids, several salts, glucose, and glycine were introduced in the resting stomachs of cats. The concentration and volume changes were recorded.